Metal-clad electric switch gear



March 9 J. MIRREY METAL GLAD ELECTRIC SWITCH GEAR 3 $heets-Sheet 1 March 9,1926. v 1,576,347

. I J. MIRREY METAL GLAD ELECTRIC SWITCH GEAR Filed Sept. 5, 1925 3-SheetsShee t 2 'March 9,1926. 4 1,576,347

. J. MIRREY METAL GLAD ELECTRIC SWITCH GEAR Filed Sept. 5, 1925 s Sheets-Sheet 5 Patented Mar. 9, 1 926.

To all whom it may concern Be it known that I, JAMES MIRREY, sub- East Boldon, in the county of Durham, 5 England, have invented certain new and useful Improvements in Metal-Clad Electric Switch Gears, of which the following is a specification.

This invention relates to metal-clad e1ectric switchgear of the draw-out type and has particular reference to switchgear for use with duplicate busb-ars. In one well known gear the main oilbreak switch which forms part of the movable or draw-out portion of the gear can be connected to' either busbar by a plug which can be removed and inserted when the main switch is open and the movable portion of the gear drawn out. It is also known to provide plug connections which can be inserted and removed into and from the busbar sockets through openings passing right through the hood or casing of the movable portion, this operation of the plugs thus being possible without moving the casing. In such a construction means have been suggested for preventing the removal of the lug until the mainswitch has been opened.

In switchgear of the type in which the construction of the main switch has been proposed to" enable either or both of the duplicate bus'bars to be placed in service. The object of the present invention is the construction'of switch ear whereby the switches or connectors being contained within the hood or casing of the movable portionand. op ed from he cu slde UNITED STATES JAMES MIRREY, OF EAST BOLDON, ENGLAND, ASS IGNOR TO A. BEYBOLLE & COMPANY LIMITED, OF HEBBURN-ON-TYNE, ENGLAND, A COMPANY OF GREAT BRITAIN.

ject of the King of England, residing at.

main switch can be moved vertically relative to the busbar portion above it aspecial them can be joined to the main switch, such PATENT OFFICE.

METAL-CLAD ELECTRIC SWITCH GEAR.

- Application filed September 3, 1925. Serial No. 54,347.

thereof without the removal-of the switch or connector from the hood or casing.

In one construction of switchgear according to this invention the usual busbar plug connectlons on the movable draw-out portion are provided inside the hood or casing with clips or other contacts adapted to be engaged by a switch arm mounted on a shaft inside, the casing and capable of being rocked or turned say by a lever or by a worm and worm wheel outside the casing. This switch may be connected to 0neside of the main oil switch and the mechanism operating it can be interlocked with the main switch operating mechanism and if desired with a separate busbar coupling switch. The switch arm or blade may however be so shaped that before leaving one busbar clip or contact it makes connection with the other and in this case the change-over switch functions also as a busbar coupler.

Instead of the one switch arm two may be employed the operating mechanism being such that each arm may be'brought into connection with either of the busbar contacts. The two arms may conveniently be mounted on a common pivot and arranged so that they make connection with opposite sides of the busbar cont-acts. Thus both arms may be in position simultaneously on one busbar contact. In such a construction the operating gear may be of such a nature that the two arms are moved in a convenient sequence. For instance if an' earthed contact be provided at each limit of motion of -the arms-the sequence may be i 1. Both arms move from an earthed con tact to No. 1 busbar contact.

2. One arm moves to No. 2 busbar contact thus coupling the busbars.

3. The other arm moves to No. 2 busbar contactthus completing the change-over without breaking the circuit.

4. Both arms move to the second earthed contact. a

If the switchgear is intended to work with such a sequence of movement the operating gear may comprisea rotatable disc with P1115 or studs engaging one or more cam sectors or quadrantsshaped so as to break switch and thevertical motion thus out removing them from the casing.

brings the arm into connection with the selected busbar contact or with an-earthed contact if such be provided and connects such contact with the oil-break switch.

Again the switch arms may have a rotary motion and when in the required position may connect the busbar clips or other contacts with similar contacts on a bar or rod. connected to one side of the oil-break switch. I

Although the change-over connectors are preferably in the form of switches, plug connectors may be employed so long as they are contained within the casing and are operable from the outside thereof withor instance plug connectors may be mounted on parallel sliding insulated bars moved by a rack and pinion or by other suitable mechanism.

In all the constructions earthed contacts may be provided and interlocking mechan sm arranged between the switches or other chan e-over connectors and the main switch an also between the change-over connectors and the busbar coupling switches if such separate switches are used.

The improved construction of switchgear according to this invention affords opportunity for the convenient and eflicient oil-immersion of the change-over switches and other connections inside the hood or casing of the movable portion.

In the accompanying drawings,

Figure l is a sectional elevation of one construction of switchgear according to this invention,

Figure 2 is a diagram of an interlocking.

circuit connection,

Figure 3 is a viewsimilar to Figure 1 but showing a modified construction pro-' viding for the operation of the switches in a certain sequence. 1

Figure 4 1s a separate view of a portion of Figure 3,

Figure 5 is a sectional elevation of another construction also according to this invention,

Figures 6 and 7 are respectively a sectional elevation and plan of a modified construction, and a Figure 8 is a sectional elevation of another construction.

All the figures are largely diagrammatic,

constructional details not essential to the unlderstanding of the invention being omittec.

Figures 1, 3, 4, 5, 6, 7' and 8 show only the movable or draw-out portion of the switchgear which in each casecomprises a hood or casing A, socket connections B and B which, when. the draw-out portion is racked in, make connection with duplicate busbars, and a third socket connection 0 joined to one side of an oil-break switch not shown, but contained in a tank beneath the base plate A As these features are known in themselves and are common to all the figures above mentioned, they are lettered similarly and their detail construction is not described.

With more particular reference to the construction shown in Figure 1, the upper busbar socket connection B is furnished inside the casing A with a contact plate I? and the lower busbar connection B with a contact plate B Within the casing is a switch arm D connected to the other pole of the main oil break switch and this switch arm D is mechanically connected by an insulating link E and crank F to a shaft G which passes through the wall of the easing A and can be partially rotated by means of a crank H, connecting rod H and crank H through worm gear H By suitable movement of this gear the switch arm D can be caused to take up three positions, (1) that shown in full lines where the busbar connection B is joined to the oil break switch, (2) that shown in chain lines where the busbar connection B is similarly connected, and (3) that shown in dotted lines where the switch arm D makes contact with an earthing connection J and the main switch is consequently earthed.

In this construction the contact member D carried by the switch arm D is shown It is preferred to provide some convenient form of interlocking mechanism to prevent the movement of the change-over switch until conditions are'suitable for suchmovement. Such interlock, for instance, may be between the main oil-break switch or the movable portion of the gear carrying it, and the change-over switch D and any known form of mechanical or electrical interlocking mechanism may be thus used.,'

the armature of an electromagnet K. Only two holes are shown but obviously a third hole might be provided corresponding to the position of the switch arm D when on the earthing connection J. The winding of the electromagnet K is connected to contact plugs L and L carried on the movable portion of the switchgear and cooperating respectively with sockets M and. M on some fixed portion of the gear. One arrangement of the interlocking circuit is shown in the diagram forming Figure 2.

In this figure two busbarsare indicated at N and N having fixed plugs N and N cooperating, when the movable portion and its casing A are racked in. with the socket connections B and B The fixed sockets M are connected in a local circuit comprising a battery 0 and push switch 0 and when the movable portion of the gear is racked out into the position shown, the interlocking electromagnet K can be energized by closing the push switch 0 so that the pin K is disengaged from the shaft G which can then be partially rotated to move the switcharm D as may be desired.

In Figure 2 the main oil-break switch is indicated at X and separate busbar coupling switchgear P is shown having busbar sockets P and P on its movable portion and drawout plug and socket connections P forming part of a local circuit includinga battery 0 and push switch 0 and -also including the fixed sockets M cooperating with the plugs L. This local circuit is controlled by an auxiliary switch P closed only when the coupler switch P is closed and thus the local circuit 0 O 'etc. can, when the plugs L and sockets M are connected and the coupler switch P is closed, be completed by the push switch 0 to release the shaft G and allow the change-over switch D to be moved;

As previously mentioned this interlocking arrangement is merely given by way of example and may be varied in many ways which are known in connection with switchgear of this general type.

Figures 3 and 4 illustrate another construction of change-over switch according to this invention in which the two switch arms D and D are pivoted side by side and can be moved in a definite sequence. The switch arm D is mechanically connected by an insulating rod D to a pivoted sector plate D forming part of a Geneva stop mechanism. The other switch arm D is similarly connected through a rod D to another sector plate D. .The sector plate D is driven by .pins R in a disc R (Figure 3) and the-plate D by pins R in another disc R (Figure 4), the discs being mounted on a shaft rotatable by anysuitable gear. This gear is not shown but it may, for instance, be similar to the gea i lustr ted in F gu e =1 for .par-

the secto r plate D and D and the pins R and R engaging them are so arranged that the switch arms D and D may be moved to take up the following positions 1. Both arms on an earthing contact J 2. Both arm move from the earthing contact J to the top busbar connection B.

Arm D advances to lower busbar connection Bflarm D remaining on B. This is the position shown in Figure 3 and the two busbars are then couplec 4. Arm I) remains on busbar connection B and arm D advances to the same busbar connection.

5. Both arms advance to a bottom earthing contact J From this last position the'sequence of operations maybe reversed by turnin' back the shaft'on which the discs R and 2 are mounted. Obviously either or both of the earthing contacts may be omitted if desired.

The details of construction of the Geneva stop work constituted by the pindiscs and sector plates need not be described in detail as mechanism of this type which act to give a pause or dwell in the movement of the dlilVEIl member are well-known in themse ves.

In Figure 5 the changeover switches are shown in the form of two blades 1) and D mounted on a rod D which can be moved .up and down'in the hood or casing A to connect either of the busbar connections B and B with a common bar or rod D joined to one pole of the main oil-break switch. earthing connection is shown at J on to which the lower blade D may be carried to earth the oil-break switch.

Figures 6 and 7 illustrate a modified construction in which the switch arms I) and D are mounted on concentric rotatable shafts D and D so that they may be moved to join either busbar connection B or B to a rod D joined to the main oil-break.

switch, or to earth that switch by connectingit to an earthing contact J 'Figure' 8 shows the change-over switches in the form of plug contacts D", D carried on bars or rods D, D moved by racks D and D and a pinion I) into and out of connection with the busbar contacts B and B The bars D and make connection with the rod 6 joined to the main oilbreak switch. a

As in the other constructions an earthing connection may be provided.

' For convenience both racks D and D are shown as operated by one pinion D but obviously the racks may be driven separately and would be so driven if the gear were intended for use as a busbar coupler scribed with reference only to one phase of the switchgear, but obviously in, for instance, three-phase switchgear, each phase may be provided with the change-over switches described and the operating gear may be linked or coupled in any known way so that the switches for the three phases operate together.

It is to be understood that the constructions illustrated are intended to beexampl s of various forms which the improved switc 1- gear according to this invention may take. The feature common to them all is that the change-over switch is-contained in the hood or casing of the movable portion of the gear and can be operated by suitable mechanism from outside that casing.

What I claim as my invention and desire to secure by Letters Patent is 1. In electric switchgear of the metalclad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, -of a main switch, a hood or casing carried by said movable portion, duplicate busbar connections mounted on said casing, at least one switch arm or connector within the casing adapted to connect either of said busbar connections to one pole of the main switch, and means outside the casing for operating said switch arm or connector.

2. In electric switchgear of the met-alclad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, ofa main oil-break switch, a hood or casing carried by said movable portion, duplicate busbar connections mounted on said casing, at least one pivoted switch arm Within the casin in electrical connection with one pole of t e main switch and adapted to be brought into contact with either of said busbar connections, and mechanism operated from outside the casing for moving said pivoted switch arm.

3. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switch-- gear, of a main oil-break switch, a hood or casing carried by said movable portion, duplicate busbar connections mounted on said casing, two pivoted switch arms Within the casing in electrical connection with one pole of the main switch and adapted to be brought into contact with either of said busbar connections, and 'mechanism operated from outside the casing for moving said pivoted switch arms in a definite sequence into and out of contact with the busbar connections.

4. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar. system, the combination with the movable or draw-out portion of the switchgear, of a main oil-break switch, a hood or casing carried by said movable portion, du-' plicate busbar connections mounted on said casing, an earthing connection within the casing, at least one switch arm or connector within the casing adapted to connect .either of said busbar connections or said -earth ng connection to one pole of the main switch, and means outside the casing for operating said switch arm or connector.

5. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, of a main oil-break switch, a hood or casing carried by said movable portion, du-

6. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, of a main oil-break switch, a hood or casing carried by said movable portion, duplicate busbar connections mounted on said casing, an earthing connection within the casing, two pivoted switch arms within the casing adapted to connect either of said busbar connections or said earthing connection to one pole of the main switch, and mechanism operated from outside the casing for moving said pivoted switch. arms into and out of contact with the busbar connections.

7. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, of a main oil-break switch, a hood or casing carried by said movable portion, duplicate busbar connections mounted on said casinggtwo pivoted switch arms withinthe casing in electrical connection with one pole of the main switch and adapted to be brought into contact with either of said busbar connections, a shaft within the casing and extending outside thereof, operative connections between said shaft and said switch arms, and means outside the casing for rocking said shaft.

8. In electric switchgear of the metal-clad horizontal draw-out type for a duplicate busbar system, the combination with the movable or draw-out portion of the switchgear, of a main oi1-break switch, a hood or casing carried by said movable portion,

duplicate busbar connections mounted on said casing, two pivoted switch. arms within the casing in electrical connection with one ole of the main switch and adapted to be rought into contact with either of said 'busbar connections, a shaft within the casing and extending outside thereof, operative connections between said shaft and said JAMES MIRREY. 

